Breeding Low-Tannin Sericea. I. Selecting for Resistance to Rhizoctonia Sp
1983
Donnelly, E. D.
A severe epiphytotic of a foliar disease caused by Rhizoctonia sp. occurred in nursery plants of sericea lespedeza [Lespedeza cuneata (Dumont) G. Don], in a breeding program to develop a low-tannin cultivar. From approximately 6,000 low-tannin nursery plants, 82 were selected that were free from disease symptoms. Most S₁ progenies of these plants proved to be susceptible in a field test; however, some appeared highly resistant. There was a close association in reaction of low-tannin lines to the fungus between 2 years. Tannin content of low-tannin lines was correlated with disease severity: as tannin decreased, disease severity increased. However, results indicated that tannin in low-tannin lines accounted for only 18% of the variation in disease severity. The remaining 82% apparently was caused by one or more genes for resistance other than the one major gene for tannin. No disease was observed on high-tannin lines. The high-tannin control cultivar had twice the tannin content as the mean of low-tannin lines.
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